Eggleston — Eruptive Rocks at Gutting sville, Vt. 379 



writer carried on intermittent, detailed work in the area. 

 A summary of results was given before the Geological 

 Society of America at Cambridge, Mass., December, 1909. 

 An abstract was printed in the Proceedings of that 

 meeting (vol. 21, p. 785, 1910). 



In connection with the present paper, acknowledg- 

 ments are due to Dr. Charles Palache, who first called the 

 writer 's attention to the Cuttingsville rocks ; to Profes- 

 sor Wolff, under whose direction this study was under- 

 taken ; to Mr. C. L. Whittle for the use of his reconnais- 

 sance map and collections ; to Professor E. A. Daly, who 



Fig. 2. 



Fig 2. Section along line A-B in fig. 1. Natural scale, 1: 28,000. 



has assisted in the preparation of the manuscript. 

 Special thanks are due to Dr. H. E. Merwin, now of the 

 Carnegie Geophysical Laboratory at Washington, D. C, 

 and to Professor C. D. Test, of the Department of Chem- 

 istry of the Colorado School of Mines, who made the 

 excellent chemical analyses accompanying this paper. 



TOPOGEAPHY. 



Cuttingsville lies in the valley of Mill Eiver on the 

 Eutland railroad, about 1,000 feet above sea (fig. 1). 

 The main eruptive body, 1-7 square miles (4 sq. km.) in 

 area, is largely confined to Granite Hill (2,007 feet, fig. 3), 

 so named from its quarries of syenite, popularly called 



Fig. 1 (p. 378). Geological map of Cuttingsville district. Scale, 1: 28,000. 

 Standard orientation. 



Stock rocks — 1, Essexite ; 2, hornblende-biotite syenite ; 3> pulaskite ; 

 4, sodalite-nephelite syenite ; 5, nordmarkite. 



Dike rocks — Dotted line, essexite porphyry. Heavy broken line, syenite 

 porphyry. Heavy full line, tinguaite. Double line, camptonite. 



Country rocks— except limestone (L), not distinguished. 



A-B, line of section. D, dike of type tinguaite. M, open cut for molyb- 

 denite. P, pit. Q, quarry. T, tunnel. 



